﻿using System.Collections;
using System.Collections.Generic;
using System.Diagnostics;

namespace System
{
    public static class ICollectionExtensions
    {
        /// <summary>
        /// Indicates whether <paramref name="collection"/> contains any of the members in <paramref name="toFind"/>.
        /// </summary>
        /// 
        [DebuggerStepThrough]
        public static bool ContainsAny<T>(this ICollection<T> collection, ICollection<T> toFind)
        {
            var found = false;

            foreach (var item in toFind)
            {
                if (collection.Contains(item))
                {
                    found = true;
                    break;
                }
            }

            return found;
        }

        /// <summary>
        /// Determines whether <paramref name="collection"/> contains all of the members of the <paramref name="toFind"/> collection.
        /// </summary>
        /// 
        [DebuggerStepThrough]
        public static bool ContainsAll<T>(this ICollection<T> collection, ICollection<T> toFind)
        {
            bool foundAll;

            if (toFind.Count == 0)
            {
                foundAll = false;
            }
            else
            {
                foundAll = true;

                foreach (T item in toFind)
                {
                    if (!collection.Contains(item))
                    {
                        foundAll = false;
                        break;
                    }
                }

            }
            return foundAll;
        }

        /// <summary>
        /// Creates an array of the items in <paramref name="collection"/>.
        /// </summary>
        /// 
        [DebuggerStepThrough]
        public static T[] ToArray<T>(this ICollection collection)
        {
            T[] array = new T[collection.Count];
            int index = 0;

            foreach (T item in collection)
            {
                array[index++] = item;
            }

            return array;
        }
        /// <summary>
        /// Creates an array of the items in <paramref name="collection"/>.
        /// </summary>
        /// 
        [DebuggerStepThrough]
        public static T[] ToArray<T>(this ICollection<T> collection)
        {
            T[] array = new T[collection.Count];
            int index = 0;

            foreach (T item in collection)
            {
                array[index++] = item;
            }

            return array;
        }
        /// <summary>
        /// Creates an array of type K, utilizing the <paramref name="converter"/> to convert from T.
        /// </summary>
        public static K[] ToArray<T, K>(this ICollection<T> collection, Converter<T, K> converter)
        {
            K[] array = new K[collection.Count];
            int index = 0;

            foreach (T item in collection)
            {
                array[index++] = converter(item);
            }

            return array;
        }
    }
}
